Comparison of Dosimetric Gains Provided by Intensity-Modulated Radiotherapy, Volume-Modulated Arc Therapy, and Helical Tomotherapy for High-Grade Glioma

Abstract

Purpose. Because of the poor prognosis for high-grade glioma (HGG) patients, it is important to increase the dose of the tumor to improve the efficacy while minimizing the dose of organs at risk (OARs). Thus, we evaluated the potential dosimetric gains of helical tomotherapy (HT) versus intensity-modulated radiotherapy (IMRT) or volume-modulated arc therapy (VMAT) for high-grade glioma (HGG). Methods. A total of 42 HGG patients were retrospectively selected who had undergone helical tomotherapy; then, IMRT and VMAT plans were generated and optimized for comparison after contouring crucial neuronal structures for neurogenesis and neurocognitive function. IMRT and VMAT were optimized with the Eclipse treatment planning system (TPS) (Version 11.0.31) and HT using TomoTherapy Hi-Art Software (Version 2.0.7) (Accuray, Madison, WI, USA). All three techniques were optimized for simultaneously delivering 60 Gy to planning target volume (PTV) 1 and 50-54 Gy to PTV2. We also analyzed the homogeneity index (HI) and conformity index (CI) of PTVs and organ at risk (OAR) sparing. Results. There was no significant difference in the PTV coverage among IMRT, VMAT, or HT. As for the HI, HT plans (PTV1 HI: 0.09±0.03, PTV2 HI: 0.17±0.05) had the best homogeneity when compared to IMRT plans (PTV1 HI: 0.10±0.04, PTV2 HI: 0.18±0.04) and VMAT plans (PTV1 HI: 0.11±0.03, PTV2 HI: 0.20±0.03). The CI value of HT (PTV1 CI: 0.98±0.03, PTV2: 0.98±0.05) was closest to the optimal value. Except for the IMRT and VMAT groups, there were statistically significant differences between the other two groups of the CI values in both PTV1 and PTV2. The other comparison values were statistically significant except for the optic nerve, and VMAT had the best sparing of the optic chiasm. The mean and max doses of OARs declined significantly in HT. Conclusions. For high-grade glioma patients, HT had superior outcomes in terms of PTV coverage and OAR sparing as compared with IMRT/VMAT.

Long-Term Survival Outcomes and Treatment Experience of 64 Patients With Esthesioneuroblastoma

“…Large MUs may increase the risk of secondary radiationinduced malignancies due to incremental scattered radiation and low-dose radiation to the other parts of body (49). Helical tomotherapy (HT) represents the progress of radiotherapy technology, as it shows superior results in terms of PTV coverage, and organs at risk (OAR) sparing compared to IMRT (50)(51)(52). For the protection of organs at risk, HT is particularly superior in protection of the brain stem and lens (51)(52)(53).…”

“…Helical tomotherapy (HT) represents the progress of radiotherapy technology, as it shows superior results in terms of PTV coverage, and organs at risk (OAR) sparing compared to IMRT (50)(51)(52). For the protection of organs at risk, HT is particularly superior in protection of the brain stem and lens (51)(52)(53). Orbital invasion is common in ENB, and is one of the most important independent prognostic factors (28).…”

Bevacizumab Combined with Intensity-Modulated Radiation Therapy on Cognitive and Coagulation Function in Postoperative Glioma Patients

“…IMRT has the characteristics of precise localization and can adjust the irradiation dose of the target region according to the shape and position of the tumour. While killing the cancer cells, it can minimize the radiation damage to the surrounding normal tissues and effectively control the growth, metastasis, and diffusion of the tumour [ 10 , 11 ]. However, due to the poor sensitivity of glioma to radiotherapy, the postoperative IMRT alone has very limited preventive value for recurrence.…”

Clinical efficacy of early postoperative intensity-modulated radiotherapy combined with Temozolomide chemotherapy in the treatment of patients with malignant glioma

“…15 Therefore, for patients with glioma surgery, radiotherapy and chemotherapy are often used as adjuvant treatments after surgery to further improve the effect of disease control and reduce disease recurrence. 16 IMRT is a new radiotherapy concept proposed in recent years 17 , which belongs to three-dimensional conformal radiotherapy. Its intensity can be adjusted according to the specific anatomical structure of the target area, so as to promote the uniformity of the entire target area and reduce radiation damage while ensuring the effect of radiotherapy.…”